The present invention relates to a process for producing dihydroxybenzene. More specifically, the present invention relates to a process for producing purified dihydroxybenzene, which is superior from an operational point of view because of absence of a step of handling a solid, and which has no need of using any additive to improve liquid separability in an extraction step.
For example, JP-A 64-38 discloses a process for producing dihydroxybenzene, which comprises the steps of:
(1) oxidizing diisopropylbenzene to obtain a reaction mixture containing di(2-dihydroperoxy-2-propyl)benzene;
(2) cleaving di(2-dihydroperoxy-2-propyl)benzene in the reaction mixture to obtain a mixture containing crude dihydroxybenzene; and
(3) obtaining purified dihydroxybenzene from the mixture containing crude dihydroxybenzene.
However, said process has a problem that purification by liquid separation is insufficient, and therefore it is necessary to use an additive to improve the liquid separability.
An object of the present invention is to provide a process for producing a purified dihydroxybenzene, which is superior from an operational point of view because of absence of a step of handling a solid, and which has no need of using any additive to improve liquid separability in an extraction step.
The present invention provides a process for producing dihydroxybenzene, which comprises the steps of:
(1) oxidizing diisopropylbenzene to obtain a reaction mixture containing di(2-dihydroperoxy-2-propyl)benzene;
(2) cleaving di(2-dihydroperoxy-2-propyl)benzene in the reaction mixture to obtain a mixture containing crude dihydroxybenzene:
(3) distilling the mixture containing crude dihydroxybenzene to obtain a fraction containing acetone from a low boiling side, and a fraction containing dihydroxybenzene from a high boiling side;
(4) distilling the fraction containing dihydroxybenzene obtained in the above-mentioned step (3) to obtain a fraction containing dihydroxybenzene from a low boiling side, and a fraction containing heavy material from a high boiling side; and
(5) mixing the fraction containing dihydroxybenzene obtained in the above-mentioned step (4) with water, and contacting the resulting mixture with an extraction solvent, followed by separating into an aqueous layer containing dihydroxybenzene and an oily layer containing impurity.